Efficient removal of norfloxacin in water using magnetic molecularly imprinted polymer.

Effective and practical materials are important for the pollution control in the environment. A novel magnetic molecularly imprinted polymer (CoFe2O4@TiO2-MMIP) was prepared based on the surface molecular imprinting technology combined with photocatalytic degradation and magnetic separation. The adsorption rate constant and maximum adsorption capacity of CoFe2O4@TiO2-MMIP are 0.21 g mg-1 min-1 and 14.26 mg g-1, respectively. The effects of experimental factors on the adsorption properties of the magnetic molecularly imprinted polymer were investigated. CoFe2O4@TiO2-MMIP had selective adsorption ability towards fluoroquinolones. The adsorption efficiency was closely related to the molecular structure, molecular weight, polarity and functional groups of the target contaminant and the removal efficiency of norfloxacin was affected by another substance obviously in binary adsorption system. The adsorption-photocatalytic recycling experiment verified that CoFe2O4@TiO2-MMIP could simultaneously complete the degradation of pollutants and in-situ regeneration, indicating good reusability. This material with selective adsorption and photocatalytic regeneration would have substantial attraction for application in the removal of fluoroquinolones.

Removal of disinfection by-products and their precursors during drinking water treatment processes.

In this study, we investigated the control efficiency of a wide variety of disinfection by-products (DBPs) (including trihalomethanes [THMs], haloacetic acids [HAAs], haloacetonitiles [HANs], haloketones [HKs], haloaldehydes [Has], and trihalonitromethanes [THNMs]) with different drinking water treatment processes including pre-ozonation, coagulation-sedimentation, sand filtration, and ozone combined with biological activated carbon (O3 -BAC) advanced treatment processes. The assessment of the treatment efficiency regarding the removal of organic matter was measured by the excitation emission matrix (EEM) spectra. There was a superior efficiency in reducing the formation of DBPs and their precursors by different drinking water treatment processes. Though some DBPs such as THMs could be promoted by ozonation, these by-products from ozonation could be degraded by the following BAC filtration process. In addition, the organic matter from the aromaticity, fulvic acid-like, protein, and soluble microbial by-products-like regions could be further degraded by the O3 -BAC treatment. PRACTITIONER POINTS: A wide variety of DBPs in different drinking water treatment processes was investigated. The treatment efficiency regarding the removal of organic matter was measured. Some DBPs such as THMs and HAAs could be increased by ozonation. The removal percentage of nitrogen precursors and organic carbon would be increased by BAC filtration.